Dashboard Formula Execution

ABSTRACT

Formulas in dashboards can be executed at a client executing web technologies such as HTML5 and JavaScript. The formulas specified by a spreadsheet file are transformed into a pre-defined notation format and then recursively evaluated. Related apparatus, systems, techniques and articles are also described.

TECHNICAL FIELD

The subject matter described herein relates to client-side execution of formulas as part of visualizations of dashboard via various web technologies.

BACKGROUND

Dashboards are graphical interfaces that provide insight into data (whether stored locally and/or stored at one or more data sources) through visual representations. Visual components used in dashboards can display data from a variety of sources, including local sources such as the embedded Excel spreadsheet or remote data sources such as databases or RSS feeds. Dashboards can be designed and executed using a variety of software applications including, for example, SAP Dashboards which is an application from SAP Business Object's Business Intelligence (BI). Various web technologies have been created that are optimized for mobile devices such as tablet computers. However, certain dashboards are not compatible or fully compatible with such web technologies. For example, difficulties can arise when executing various formulas specified by spreadsheets via browsers and other similar technologies.

SUMMARY

In one aspect, data comprising a spreadsheet file in a text-based, language-independent data interchange format is received. The spreadsheet file includes at least one cell including at least one formula. Thereafter, a request is accepted to evaluate the at least one cell followed by recursive evaluation of the at least one cell. Rendering of a dashboard is then initiated using the spreadsheet file, a dashboard structure file, and the recursive evaluation.

The dashboard can be rendered in a browser such as an ECMAScript-enabled browser. The text-based, language-independent data interchange format can be JAVASCRIPT Object Notation (JSON) format. The dashboard can be further rendered using a dashboard structure file.

In some variations, a representation of one or more cell having at least one formula can be transformed into a pre-defined notation format such as a postfix notation. Each formula in the transformed notation can include one or more tokens. With such a variation, the recursive evaluation can include creating a result stack and for each token in the transformed representation: (i) if the token corresponds to a value, pushing the token onto the result stack, (ii) if the token corresponds to a function, popping required arguments off the result stack, evaluating the function, and pushing the result of the function onto the result stack; and/or (iii) if the token corresponds to at least one cell reference: recursively fetching the value of the at least one referenced cell. The tokens corresponding to a value can correspond to a literal or constant value. The value of the at least one reference cell can be recursively fetched if the cell comprises at least one formula.

The received data can be received from at least one server, and the accepting, evaluating and initiation of the rendering can be executed by at least one client remote from the at least one server.

Computer program products are also described that comprise non-transitory computer readable media storing instructions, which when executed by at least one data processor of one or more computing systems, causes the at least one data processor to perform operations herein. Similarly, computer systems are also described that may include one or more data processors and a memory coupled to the one or more data processors. The memory may temporarily or permanently store instructions that cause at least one processor to perform one or more of the operations described herein. In addition, methods can be implemented by one or more data processors either within a single computing system or distributed among two or more computing systems.

The subject matter described herein provides many advantages. For example, the current subject matter enables a web-based viewing solution to render documents such as dashboard documents using only HTML5, JavaScript and standard web technologies with the corresponding formulas being evaluated on the client-side. In particular, while it is normally difficult to access and to evaluate the formula in a spreadsheet from within a spreadsheet, examples herein do this. Also in particular, dashboard documents can be converted to a JavaScript-friendly format which is then rendered in any modern browser and device, including iOS devices. Such dashboard documents are complementary to those dashboard documents that are exported in other formats such as Flash (SWF). In addition, the current subject matter is advantageous in that it can be used to provide a dashboard JavaScript viewer that obviates the need for an intermediate publishing step by converting the dashboard to its JSON representation from an XLF file directly.

The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a screenshot illustrating a sample dashboard in a dashboard designer application;

FIG. 2 is a diagram illustrating a client/server architecture;

FIG. 3 is a process flow diagram illustrating conversion of an XLF format file into JSON;

FIG. 4 is a screenshot illustrating the dashboard of FIG. 1 with data originating from local and remote data sources;

FIG. 5 is a screenshot of a spreadsheet illustrating cell dependency management;

FIG. 6 is a screenshot of a spreadsheet illustrating a first cell with a formula referencing a second cell to another cell using a formula;

FIG. 7 is a diagram illustrating recursive evaluation of the formula in the first cell of FIG. 6;

FIG. 8 is a diagram illustrating an interface with a graphical user interface prompt element; and

FIG. 9 is a process flow diagram for client-side execution of dashboard formulas.

DETAILED DESCRIPTION

FIG. 1 is a screenshot 100 that shows a sample dashboard in a dashboard designer application that includes a palette 140 of chart types and components that can be dragged and dropped onto a work surface 105. The visual component 110 titled ‘Local Pie Chart’ is displaying data from a local source while the visual component titled 120 ‘Remote Bar Chart’ is displaying data from a remote data source. In addition, the dashboard can include a spreadsheet section 130. The spreadsheet section 130 can include relevant data and/or define calculations that forms which relevant data that forms part of the visualization. This dashboard can be published into one or more formats. For example it is rendered in a web browser.

The diagram 200 of FIG. 2 illustrates a three-tier architecture with a client 210 and a server 220 coupled to a back-end business intelligence (BI) suite 230) that communicate over HTTP. With this arrangement, the client 210 can be a web browser, while the server 220 can be a Java web application bundle deployed on a web server such as Apache Tomcat or Jetty. The server 220 can: (i) parse and convert a dashboard container file to JavaScript Object Notation (JSON), if not in this format already, (ii) determine prompts required to be answered for a data source, and/or (iii) retrieve data from remote data sources at the behest of the client 210.

The client 210 can (i) display the visual components in the document, after populating them with data, (ii) request data from remote data sources from the server 220 and/or obtain local data, (iii) evaluate formulae, if any, in the local data and populating a visual component with the final result, and/or (iv) display prompts in the dashboard, if any, to filter on available data from a remote data source. It will be appreciated that some or all of the functionality of the server 220 can be executed on the client 210 and/or as part of an integrated BI suite 230. For example, various conversions or transformations can be performed locally at a client 210 or within the BI suite 230. By performing the conversions or transformations there this can reduce the need for an add-on application, middleware, etc.

The current subject matter is applicable to various types of dashboard features and components. For example, the current subject matter is applicable to data retrieved from a semantic layer overlying a data source, for example, SAP's Dimensional Semantic Layer (DSL) and spreadsheet data consumption, on-the-fly Excel formula evaluation and various widgets such as visualizations: charts (e.g., pie, line, bar), tables, maps; content holders: tabs, sheets; interactivity elements: controls (e.g., sliders, dials, prompts); and support for DSL prompting. Prompting is where a user is asked for input that parameterizes a query or how a result set is formatted.

A dashboard container file is used that can contain one or more metadata files and one or more spreadsheet files. Examples include files using the extension .XLF which is the extension used for SAP Dashboards dashboards. With this particular example, the container file is an XLF file comprising an XLS spreadsheet and an XML document, compressed into a single file. For example, together in ZIP file format. XML in this regard refers to Extensible Markup Language (XML), a standardized data format notation, as defined by the World Wide Web Consortium (W3C). In some variations, the XML format stores metadata about the dashboard in a dashboard structure file. This metadata includes information such as: dashboard components, component properties, component association with cells in an associated spreadsheet, data sources, dashboard layouts, dashboard behavior, etc. Components can be organized into categories like functionality: input components, output components, layout components. It will be appreciated that the current subject matter can apply, in addition to XLF files, to a wide variety of container files including bundles having multiple spreadsheet files (and are collectively referred to as container files unless otherwise specified).

JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format. It was derived from JavaScript a programming language that implements the ECMAScript Programming Language Standard. JSON defines a small set of formatting rules for the portable representation of structured data. While the disclosure is mainly directed to the use of JSON, it will be appreciated that the current subject matter can use other data interchange formats having similar properties.

JSON is widely used for JavaScript-based web applications because it is a native JavaScript data format. One obvious benefit of this is that web applications can avoid the overhead of converting to and from other data formats. This leads to leaner processing times and a smaller memory footprint for the application. To exploit the benefits of JSON listed above, the metadata in the XML document can be converted into another format such as JSON. This is a one-time conversion that occurs when the dashboard is opened for viewing. After the metadata is converted into JSON, the web application uses the JSON representation of the document's metadata for all subsequent work.

With further reference to the diagram 200 of FIG. 2, the client 210 sends a request to the web server 220 via a DSL query to render a dashboard. This request can be in various formats and handled via various protocols including JSON/REpresentational State Transfer (REST), and XML/Simple Object Access Protocol (SOAP). The web server 220, in response to the request, executes one or more remote data source queries of the BI suite 230. The BI Suite 230 then delivers a container file (e.g., an XLF format file) responsive the remote data source queries to the web server 220. The web server 220 can, as will be further described below, convert/parse the XLF file to JSON. This can be offered as a web service. In addition, a software development kit (SDK) can be implemented on a dashboards server (which may be integral to the web server 220 or coupled thereto) to further the conversion to JSON. The web server 220 can transmit data to the client 210 comprising the JSON representation of the dashboard via REST protocol. The client 210 can then render the dashboard using, for example, a browser executing HTML/JavaScript, SVG, a JavaScript library to display given digital data into dynamic graphics, and/or using visualization tools, such as, Google Visualization, and Data-Driven Documents (D3).

FIG. 3 is a diagram 300 illustrating various stages involved in converting a container file 305 comprising an XML document 315 and an XLS document 335 to a JSON file 360.

A method to convert the XML document in the XLF file to a temporary DOM and from there into JSON is described in pseudo-code below:

-   -   1. Open, using an XLF extractor 310, the XLF document using a         ZipInputStream;     -   2. Create a XMLStreamReader (Java SDK StAX implementation) from         the XML portion of the XLF (to result in the XML document 315);     -   3. An XMLStreamReader parser 320 is advanced until it encounters         one of a plurality of specified events, such as:         -   a. Component             -   i. Component properties are parsed into key-value pairs             -   ii. Sub-components are recursively parsed             -   iii. Dependencies on data sources are parsed         -   b. Data Source             -   i. Data source properties are parsed into key-value                 pairs             -   ii. Dependencies between data sources and cells are                 parsed         -   c. Other style-related attributes.     -   4. The result of the parsing is a simple dashboards DOM (320)         storing the information collected;     -   5. The dashboards DOM is then traversed (325) in a depth-first         traversal through the components and data sources. The JSON.org         Java classes are used to output the resulting JSON format (360).

The spreadsheet file 335 (e.g., XLS document) is the second file inside the container file 305 (e.g., zipped dashboards document (XLF)). The spreadsheet file 335 can be, for example, a Microsoft Excel spreadsheet. The spreadsheet file 335 comprises components such as sheets, rows and cells. This spreadsheet file 335 can be used in the dashboards document in a few different ways:

-   -   1. Cells in the spreadsheet can contain formulae and data;     -   2. Cells in the spreadsheet can be used as depositories for data         retrieved from at least one remote data source;     -   3. Cells in the spreadsheet can be used as data sources for         visual components in the dashboard; or     -   4. Cells in the spreadsheet for storing input from users         including prompt values.

The web application can receive the metadata about the document in JSON format (as part of the above-described XML to JSON conversion process). To maintain consistency with this approach, the data in the spreadsheet file 335 (e.g. XLS document) can also be converted into JSON and passed into the web application.

Converting a spreadsheet file 335 into the JSON format required by the web application can be done using an Apache POI library 340, a Java-based Excel parsing and converting library. Once the spreadsheet file 335 is loaded by the Apache POI Library 340, it can parse the contents and convert it into a first intermediate state, an Apache POI Object 345. The parser can use a straightforward mechanism to pass over the spreadsheet, rows and cells that make up the document to generate the object 345. The first intermediate state, the Apache POI Object 345 can be converted into JSON by one of two processes: the operation of a Converter for Data in Apache POI Object to JSON 350, and a Converter for Formulae in Apache POI Object to JSON 355. The data can be converted without use of further intermediate states into JSON format. The formulae can be handled by the Converter for Formulae in Apache POI Object to JSON 355 that iterates over the spreadsheet, rows and cells that make up the document and makes use of a further intermediate state. On encountering formulae, the Converter for Formulae in Apache POI Object to JSON 355 can extract the formulae. The Apache POI library's native formula representation is a postfix notation, which is advantageous for programmatic stack-based evaluation. The postfix representation of the formulae is a second intermediate state for converting to JSON. The Converter for Formulae in Apache POI Object to JSON 355 can produce the postfix representation and then convert it to JSON 360. This postfix notation becomes the JSON representation of that formula, for that particular cell.

Various types of XML parsers can be used, including, for example, document object model (DOM) parsers, pull parsers, and push parsers. DOM-based parsing reads the entire XML document into memory and builds a tree-based data structure, from which data can then be retrieved on demand. This increases the memory footprint of the application and can result in longer latencies, since the entire document has to be read and loaded into main memory all at once. Pull parsing gives the calling application more control over the document that's being parsed, by letting the calling application control the parser. Push parsing is the converse of pull parsing where the parser controls parsing events and the calling application has to respond to events from the parser.

In some implementations, a pull parser can be utilized because it provides a smaller memory footprint and lower response times, as well as letting the calling application retain control of the parsing process. For example, a StAX parser such as that included in Oracle's Java 1.6 Software Development Kit (SDK) can be used. Using the parser, a lightweight DOM, representing the dashboard, can be built in memory, based on the metadata from the dashboard file.

The metadata converted from XML into JSON can include:

-   -   1. Components, e.g., graphs, bar charts;     -   2. Data sources, e.g., a list of cells in the spreadsheet or a         connection to a database;     -   3. Properties, e.g., attributes of charts such as line colours         or font sizes; and     -   4. Data bindings, e.g., how data connections are bound to visual         components such as charts.

The DOM, representing the dashboard, built in main memory is much smaller than the XML DOM that would have been built with a DOM-based XML parser because it excluded properties that were not required. Once the custom DOM, representing the dashboard, is completely built in memory, it is transformed to JSON and returned to the web browser. For example, this is done when the web browser makes a request for it (which request can include an ID corresponding to the DOM). The actual transformation of the DOM into a JSON string can be achieved by a depth-first recursive traversal of the tree.

Once the web application requests and receives the JSON payload representing the dashboards document, it is up to the client-side JavaScript (which may be part, for example, of a browser, etc.) on the client 210 to display the visual components. FIG. 4 is a screenshot 400 that shows the two types of data sources that can be used to populate a visual component in a chart. Cells B1 through C4 show data stored in the spreadsheet. While cells G2 through H6 show the results of query (not shown) to a remote data source. When a dashboard document is received by the client 210 in JSON format, the information about the data sources can be preserved and available in the JSON object. On loading the JSON object from the server, the client 210 identifies the visual components present in the dashboard document. Each component is then rendered, but only after the data that populates the component is available from a data source, remote or local.

With further reference to FIG. 4, Remote Bar Chart 120 renders the results of the remote data source that it depends on, while Local Pie Chart 110 shows the data obtained from the local data source, i.e., the spreadsheet document that was present in the container file (e.g., an XLF file, etc.). When the remote data source has finished retrieving its data, it notifies the components listening to it, such as, a visual component that the data is available and the visual component renders itself, using the supplied data. This form of notification is an example of events and event listening, where an entity can register as a listener for any type of event on a different entity.

When the client 210 receives the JSON representation of the dashboards document from the web server 220, the document can be analyzed to determine the components, data sources and their dependencies between each other in the dashboard. When a component depends on a data source it can register a listener to be notified whenever the data source fetches new data. A data source (X) can also register a listener on another data source (Y) if X depends on the result of Y.

If a component depends on a data source in order to render then the act of rendering that component can occur in multiple asynchronous steps. First, the component can notify the data source that data is required. The component can then continue the flow of execution (without blocking/waiting for the data source) knowing that once the data source has fetched data the component's listener will be notified of the new data. The data source can then schedule a fetch of the data (the exact mechanics of this depends on the data source). When the data source finishes fetching the data, all listeners, including any components who notified the data source, can be notified. At this point the original component, and any other that notified the data source, can perform the rendering.

By asynchronously triggering the data fetch, fetching the data and notifying data source listeners the data sources need not perform the act of fetching data until required. This asynchronous technique can also allow data source fetching to be done in batches by potentially combining multiple fetches of the data into one. For example, if multiple components attempt to render within a short window of time, the data source may only fetch the data once and then notify all dependent components of the data change.

A method for setting up an event infrastructure can be as follows:

-   -   1. The client 210 receives the JSON representation of the         dashboard document from the web server 220;     -   2. The JSON representation is used to construct a model         representing the components and data sources;     -   3. Components are recursively created because a component can         contain multiple sub-components;     -   4. Dependencies between components and data sources are         discovered and appropriate event listeners are registered.

Spreadsheets can also contain inter-cell dependencies, when a formula depends on the value of another cell. An example of this can be seen in the diagram 500 of FIG. 5. In B5, Formula A depends on cells B2, B3 and B4. When the value in B3 is changed to ‘2’ from ‘5’, then Formula A is notified of this change and cell B5 is updated. This type of notification and update management is native to some spreadsheet applications such as Microsoft Excel, but needs to be carefully simulated in JavaScript, so that the web application may take advantage of this type of event propagation.

Notification and update management can be achieved by iterating over the JSON representation of the spreadsheet file, and finding all dependencies between all formulae. As seen in FIG. 5, if Formula A depends on cells B2, B3 and B4, Formula A registers a listener on B2, B3 and B4. If either B2, B3 or B4 are updated, then the event listener registered by Formula A is notified. Formula A treats this notification as a change to itself and can further notify all listeners that have registered with Formula A. In this way, a change in a cell can be propagated through a chain of listeners without actually evaluating the formula itself. This approach can be advantageous in that that formulae are lazily executed, which leads to a reduction in the memory footprint of the application.

A method to set up cell dependencies can be as follows:

-   -   1. The client 210 receives the spreadsheet file as JSON from the         web server 220     -   2. For each sheet, row and cell,         -   a. If the cell contains formula F1             -   i. If formula F1 contains a reference to another cell,                 C1                 -   1. An event listener is registered on C1 which                     propagates the event to the listeners of F1

One type of data source is the spreadsheet file which was converted to JSON at the web server 220 and sent to the client 210. Spreadsheet cells can contain not only raw data, but also formulae, which might contain references to other cells or mathematical functions. If a visual component relies on cells that contain formulae, these formulae have to be evaluated in order to display that component. As the formula is a JSON object, like the rest of the document, there is very little overhead in evaluating the formula in JavaScript. Postfix notation lends itself to straightforward evaluation on a stack-based evaluator, as seen below.

With reference to the diagram 600 of FIG. 6, a formula (C5) contains a reference to B5 (also a formula). When a cell contains a reference to another cell in its formula, the formula can be evaluated using recursion. One example recursion technique is illustrated in the diagram 700 of FIG. 7; when formula C5 is evaluated, B5 is recursively evaluated. In this manner, a formula that was originally contained in an Excel spreadsheet can be received and evaluated using JavaScript in a client-side application.

A method for evaluating a spreadsheet formula in its JSON representation can be as follows:

-   -   1. Create a result stack     -   2. For each token of the formula in postfix notation         -   a. If the token is a value (that is, literal or constant),             push it onto the result stack         -   b. If the token is a function             -   i. Pop the necessary function arguments off the result                 stack             -   ii. Evaluate the function             -   iii. Push the result of the function onto the result                 stack         -   c. If the token is a cell reference             -   i. Fetch the value of the referenced cell(s),                 potentially in a recursive fashion if that cell is also                 a formula

Dashboards can include functionality including prompts and answering prompts to provide input, customizations, drill downs, etc. to the dashboard. Such prompts are normally answered by asking the user to input a value. An example of a prompt in a dashboard would be filtering values by a certain time period, such as, a year or a quarter. If a dashboard is designed to display sales for a certain quarter based on the answer to a prompt, then when the user selects ‘1’ as the quarter, the dashboard displays sales for the first quarter.

On top of interactive prompting in dashboards, prompts can be answered using values from certain cells. In the example above, if the dashboard was set up to use the value in a cell, e.g. C3, as the answer to the ‘Quarter’ prompt, then it would show all sales values for the first quarter, just as if it had been specified in an interactive text field.

Cell values can also be designated as the output depositories of interactive components such as sliders. For example, in the diagram 800 of FIG. 8, the value for a slider graphical user interface element 810 for a pie chart 820 can be changed from 1 to 4, and when the slider is moved, cell C3 is updated with the slider's current value. If cell C3 is designated as both the input source for a prompt and the output depository for an interactive component, then the answer to a prompt can be supplied from the cell value and updated as the value in the cell is updated.

The process of propagating the events that are fired when the cell is updated due to a change in the visual component, all the way to the redrawing of the dashboard, is described below. In the example of FIG. 8, the slider 810 writes its updated value to cell C3. The updated cell then broadcasts to its listeners that it has been updated. A subsequent query directly or indirectly consumes the content of a cell and launches a query using the output as is or modified as a prompt. The query results are populated in the designated result area. The listeners to this area are alerted on update. The listeners can include a chart.

Prompting can be implemented in JavaScript as follows:

-   -   1. On document setup         -   a. For any prompts answered by a cell, register a listener             on that cell which reruns the prompt's query;     -   2. On query execution, fetch the prompts that need a value in         order to run this query (this may be a remote call to a server).         When the prompts are known, an asynchronous callback executes         Step 3.     -   3. Once the prompts are known, each must be answered         -   a. If a prompt is bound to a cell, fetch the cell value and             proceed to Step 4. Note that this cell value is fluid and is             subject to change by, for example, the output of other             components such as sliders.         -   b. Otherwise display a visual user input component. When the             user submits input, an asynchronous callback executes Step 4     -   4. If not all prompts have been answered, repeat Step 3.     -   5. Execute the query (this may be a remote call to a server)         using all the prompt answers from Steps 3-4.

Additionally, dashboards can consist of a mixture of local and remote data sources. Documents that contain remote data sources usually refer to other objects deployed with the BI suite 230, and thus require a working installation of the BI suite 230 in order to retrieve data. However, visual components that rely on local data sources, such as the cells in the spreadsheet document do not need a working BI suite 230 install in order to display correctly.

With the current subject matter, a JavaScript dashboards viewer can be provided that allows a user to upload (via client 210) a dashboard to the server-side service (via server 220) and view the visual components that rely on local data sources, in the absence of a BI suite 230 install. This arrangement can be achieved by identifying the local data sources and the components that depend on them during conversion of a dashboard container file (e.g., XLF file) to JSON, without maintaining a copy of the file on the server. When the browser on the client 210 receives the JSON representation of the document and renders the visual components, the data from the local data sources exists in the JSON representation and can be retrieved immediately, without any remote calls to the server 220. If the document has remote data sources, then data retrieval from those data sources can fail in the absence of a BI suite 230 install.

Thus, a dashboard which would previously be viewed after publication and usually in a ‘managed’ environment can now be viewable in an ‘unmanaged’ state, due to:

-   -   1. Independence from the BI suite 230, which was used to host         the published artifact, in the shown example, the SWF file         (representation of the dashboard);     -   2. Independence from the need to publish any sort of         intermediate artifact at all, allowing users to view the         dashboard from the raw XLF file itself.

The following are a sequence of steps that can be performed each time a managed document with mixed local and remote sources is viewed using the server-side service:

-   -   1. The client 210 uploads an XLF file to the server 220 using         HTTP;     -   2. The server 220 parses the file and returns JSON to the client         210;     -   3. The client 210 displays the visual components that depend on         local data sources; and     -   4. Visual components that depend on managed remote data sources         are not displayed, due to the lack of a managed environment.

FIG. 9 is a process flow diagram 900 in which, at 910, data is received that includes a spreadsheet file in a text-based, language-independent data interchange format including a representation of each populated cell. In one variation, this is JSON format. In addition, the spreadsheet file includes at least one cell having at least one formula. Thereafter, at 920, a check is made to see if the formula(s) is/are in a pre-defined notation format and, if not, the representation of each cell having at least one formula can be transformed into the pre-defined notation format. In some implementations, the pre-defined notation format is a postfix notation. In some embodiments the transformation to the pre-defined notation format is already done at the server and the data passes this check. Then, at 930, a request to evaluate at least one cell. For example, receive a request to evaluate the spreadsheet, or a specified portion thereof. For example, the request to evaluate could be the result of a request to render a dashboard, as specified by a dashboard structure file, and associated with the spreadsheet, and the specified portion of the spreadsheet is associated with the dashboard. Each cell needed for the evaluation of specified portion is evaluated at 940. The evaluation can be done recursively over the cells in the spreadsheet file that are needed for the evaluation of the specified. A dashboard, as specified by a dashboard structure file, and associated with the spreadsheet, can then be rendered, at 950, on the client.

Various implementations/aspects of the subject matter described herein may be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and/or combinations thereof. These various implementations may include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

These computer programs (also known as programs, software, software applications or code) include machine instructions for a programmable processor, and may be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, apparatus and/or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor.

To provide for interaction with a user, the subject matter described herein may be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user may provide input to the computer. Other kinds of devices may be used to provide for interaction with a user as well; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic, speech, or tactile input.

The subject matter described herein may be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a client computer having a graphical user interface or a Web browser through which a user may interact with an implementation of the subject matter described herein), or any combination of such back-end, middleware, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (“LAN”), a wide area network (“WAN”), and the Internet.

The computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

Although a few variations have been described in detail above, other modifications are possible. For example, the logic flow depicted in the accompanying figures and described herein do not require the particular order shown, or sequential order, to achieve desirable results. In addition, it will be appreciated that the current subject matter is applicable to different formats other than those specified herein. Furthermore, it will be appreciated that the various conversion techniques of spreadsheet files and XML files can be used independently from the particular applications described herein. Other embodiments may be within the scope of the following claims. 

What is claimed is:
 1. A method comprising: receiving data comprising a spreadsheet file in a text-based, language-independent data interchange format, the spreadsheet file comprising at least one cell including at least one formula; accepting a request to evaluate the at least one cell; recursively evaluating the at least one cell; and initiating rendering of a dashboard using the spreadsheet file, a dashboard structure file, and the recursive evaluation.
 2. A method as in claim 1, wherein the dashboard is rendered in a browser.
 3. A method as in claim 2, wherein the browser is an ECMAScript-enabled browser.
 4. A method as in claim 1, wherein the text-based, language-independent data interchange format is JAVASCRIPT Object Notation (JSON) format.
 5. A method as in claim 1, wherein the dashboard is further rendered using a dashboard structure file.
 6. A method as in claim 1, further comprising transforming a representation of each cell having at least one formula into a pre-defined notation format prior to the recursive evaluation.
 7. A method as in claim 6, wherein the pre-defined notation is a postfix notation.
 8. A method as in claim 6, wherein each formula in the transformed notation comprises one or more tokens, and wherein the recursively evaluating comprises: creating a result stack; for each token in the transformed representation: if the token corresponds to a value, pushing the token onto the result stack; if the token corresponds to a function: popping required arguments off the result stack; evaluating the function; pushing the result of the function onto the result stack; if the token corresponds to at least one cell reference: recursively etching the value of the at least one referenced cell.
 9. A method as in claim 8, wherein tokens corresponding to a value correspond to a literal or constant value.
 10. A method as in claim 8, wherein the value of the at least one reference cell is recursively fetched if the cell comprises at least one formula.
 11. A method as in claim 1, wherein the received data is received from at least one server, and wherein the accepting, evaluating and initiation of the rendering are executed by at least one client remote from the at least one server.
 12. A non-transitory computer program product storing instructions, which when executed by at least one data processor forming part of at least one computing system, result in operations comprising: receiving data comprising a spreadsheet file in a text-based, language-independent data interchange format, the spreadsheet file comprising at least one cell including at least one formula; accepting a request to evaluate the at least one cell; recursively evaluating the at least one cell; and initiating rendering of a dashboard using the spreadsheet file, a dashboard structure file, and the recursive evaluation.
 13. A computer program product as in claim 12, wherein the dashboard is rendered in a browser.
 14. A computer program product as in claim 13, wherein the browser is an ECMAScript-enabled browser.
 15. A computer program product as in claim 12, wherein the text-based, language-independent data interchange format is JAVASCRIPT Object Notation (JSON) format.
 16. A computer program product as in claim 12, wherein the dashboard is further rendered using a dashboard structure file.
 17. A computer program product as in claim 12, wherein the operations further comprise: transforming a representation of each cell having at least one formula into a pre-defined notation format prior to the recursive evaluation.
 18. A computer program product as in claim 17, wherein each formula in the transformed notation comprises one or more tokens, and wherein the recursively evaluating comprises: creating a result stack; for each token in the transformed representation: if the token corresponds to a value, pushing the token onto the result stack; if the token corresponds to a function: popping required arguments off the result stack; evaluating the function; pushing the result of the function onto the result stack; if the token corresponds to at least one cell reference: recursively etching the value of the at least one referenced cell.
 20. A system comprising: at least one data processor; and memory storing instructions, which when executed by one or more processors, result in operations comprising: receiving data from a remote server comprising a spreadsheet file in a text-based, language-independent data interchange format, the spreadsheet file comprising at least one cell including at least one formula; accepting a request to evaluate the at least one cell; recursively evaluating the at least one cell; and initiating rendering of a dashboard using the spreadsheet file, a dashboard structure file, and the recursive evaluation. 